The present disclosure generally relates to a method and system for monitoring the respiratory or cardiac cycles of a subject. More specifically, the present disclosure relates to a device that is able to discern the cardiac or respiratory cycles of a patient which can be used to monitor respiration to generate a triggering signal for use with a medical imaging system or in other applications.
Multi-modality medical imaging systems exist that scan using different modalities, for example, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and Single Photon Emission Computed Tomography (SPECT). During operation, the image quality of the conventional imaging systems may be affected by the motion of the object being imaged. In particular, motion of the imaged object can produce artifacts that degrade the image quality. More specifically, image artifacts are produced by movement of the object during image acquisition. Respiratory motion is a common source of involuntary motion in patients encountered in medical imaging systems. The respiratory motion may lead to errors during image review, such as when a physician is determining the size of a lesion, determining the location of the lesion, or quantifying the lesion.
One known method for reducing the imaging artifacts is to sort the image data into a plurality of gates based on a respiratory signal. One of the gates is then selected as the reference gate and the remaining gates are then registered to the reference gate. For example, the reference gate selected typically includes information that is collected at the end of the patient's breathing cycle. However, the reference gate having information collected at the end of the patient's breathing cycle may not include optimal information for registering the remaining gates. For example, the reference gate having information collected at the end of the patient's breathing cycle may not include a fewer number of pixels or pixels having a reduced pixel intensity. Thus, when the remaining gates are registered with the reference gate, the quality of the resultant image may be reduced.
In order for gating to be used with a medical imaging system, a triggering signal must be acquired from the patient that is related to the respiratory movement of the patient. Technologies currently exist to provide such a triggering signal. However, existing technologies are expensive, large, and bulky and in some instances difficult and time consuming to properly set up on the patient and are potentially uncomfortable for the patient to wear for extended periods. For this reason, a need exists for a small, unobtrusive, cost-effective monitoring device that is easy to use by both the clinician and the patient, improves workflow rates with respect to the medical imaging, system, improves performance and is comfortable for the patient.